Sunday, October 13, 2013

IS THE PREGNANCY RDA FOR VITAMIN A ADEQUATE?

The RDA of vitamin A for pregnant women is only 2,600 IU—just 300 IU more than the RDA for women who are not pregnant. To obtain this figure, the scientists at the Institute of Medicine (IOM) made the following calculation: first, they ascertained from previous reports the amount of vitamin A stored in the livers of fetuses that were spontaneously or voluntarily aborted between 37 and 40 weeks; second, they doubled this figure, assuming that half of the fetal vitamin A stores exist in the liver; and third, they divided this amount over the number of days in the last trimester, during which they presumed this vitamin A would accumulate.20
There are several problems with this calculation. Since the fetuses were aborted, we have no idea what their future health would have been like—their visual acuity, their hearing, their intelligence, their facial and dental features, their reproductive health, or their length of life. And the function of vitamin A, of course, is not to be stored but to be used. The fetus does not simply hold on to vitamin A to use it after birth, but rapidly uses and metabolizes it to regulate the entirety of its growth and development. Granted, the IOM acknowledges that it has only used this data because better data do not exist—yet it is important to emphasize just how little the data tell us.

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